I too would be suspicious of the nose geer being replaced. Why would one just up and replace the nose gear unless some damage was done? This may be logged as an "upgrade" but could have been a damage scenerio. Find out who else is aware of the plane at the airport and what they can tell you about it. If damage was done on the airport and it is a smaller airport, about everyone at times knows about it. Run the N number through the clubs search. This could show some things (but may not show other problems with the plane. ) Be civil to the owner--maybe he would go in as partners. If this is agreeable, have things in writing and check on other flying club by-laws etc. You may own a plane with a guy that only flys rarely, but still wants a plane to fly.